Re: Is this a problem in mathematica?
- To: mathgroup at smc.vnet.net
- Subject: [mg74643] Re: Is this a problem in mathematica?
- From: dh <dh at metrohm.ch>
- Date: Thu, 29 Mar 2007 02:35:11 -0500 (EST)
- References: <eud3g1$l0t$1@smc.vnet.net>
Hi,
Minimize searches the global minimum and if you read the manual, there
you find: "Even if the same minimum is achieved at several points, only
one is returned".
To get both x values, you can e.g. write the distance as a function of
x: dist = x^2 + ((x^2 + 1) - 2)^2 and search extremal points like:
Solve[{D[dist,x]==0,D[dist,y]==0},{x}]
Daniel
traz wrote:
> Let's say I wanna solve this problem:
>
> Determine point(s) on y = x^2 +1 that are
> closest to (0,2).
>
> So in mathematica:
>
> minDist = (x - 0)^2 + (y - 2)^2;
> Minimize[minDist, y == 1 + x^2, {x, y}]
>
> Output will give you: x -> -1/Sqrt[2], y -> 3/2
>
> but x also has another answer: +1/Sqrt[2]. Is this a problem in mathematica or can my code be changed to output the other value of x for the minimum distance?
>